1. Field of the Invention
The present invention relates to an automatic detector for starting security cameras, especially to those detecting light in the area and infrared energy emitted from human bodies to switch the security cameras on or off.
2. Description of the Prior Art
Security cameras are disposed on certain areas of factories such as the main gate, doorway, corridors, passages, and stairways for the sake of surveillance. These CCD cameras monitor for 24 hours day after day and the related video camera recorders are also recording continuously. The most common specifications of video tapes includes 60 minutes, 90 minutes and 120 minutes. Thus the video tapes for storage of 24-hour recording pictures are in large amount. Even the tapes can be reused after a period of time, the space for keeping these tapes in storage is quite large.
While nobody passed by, security cameras and video camera recorders are still monitoring and recording so the useless pictures occupy most of the pictures and increase the number of tapes stored.
Furthermore, the low light of the environment will affect the quality of pictures while recording so there is difficulty on the identification of the person inside the picture. Illuminator can be used but then the expense of electricity increases and the energy is wasted while no one passes the area.
It is therefore the primary object of the present invention to provide an automatic detector for starting security cameras that automatically switch on security cameras by detecting infrared energy emitted from human bodies in order to decrease the number of video tapes with no-man""s pictures therein.
A further object of the present invention is to provide an automatic detector for starting security cameras that automatically switch on illumination devices by detecting the light of the area in order to avoid the waste of energy.
The device comprises a detection module disposed on a video camera. The detection module therein includes a regulator circuit, a light-sensitive circuit, a switch circuit, and a passive infrared sensor circuit, and a recorder control circuit, wherein the passive infrared sensor circuit is connected to the main body of security cameras, the switch circuit is connected to a light and the recorder control circuit is connected to a video camera recorder. In. accordance with the structure mentioned above, the main body of the security cameras and the video camera recorder is started by the passive infrared sensor circuit to detect the infrared energy emitted from human bodies. Therefore, the amount of no-man""s-picture is decreased and the number of video tapes is also reduced. If the light of the environment is insufficient, the switch circuit is activated by the light-sensitive circuit to switch the light on so that the light is enough to make the pictures clearly.